Congo is globaly known for its minerals resources. But, other potentialities such as fisheries resources and Peatlands are not well known. These natural resources contribute in the food security and nutrition and peatlands reduce the global warming by stocking the greenhouse gases (Carbon dioxide). In order to value these resources which play a critical role in the well-being of the living beings, and to share scientific knowledge based on the environment and fisheries stock assessment, we have written this book which describes the Lake Mai-Ndombe Ecosystem; Describes a simplest and cheapest method of fisheries stock assessment and present an E-article on Population Dynamic of Clarias gariepinus in Lake Mai-Ndombe.After reading this book, the reader will get at least one portion of wealth. No matter what is the activity: scientist, decision maker, manager, business person, tourist, student, etc. The reader will get profit, guaranteed!